1. Field of the Invention
This invention relates to information playback systems and more particularly, to an improvement in magnetic recording media such as magnetic video or audio tapes.
2. Description of the Prior Art
Magnetic tapes are usually made smooth on the surfaces thereof in order to attain good electromagnetic characteristics. At the same time, they are required to have a certain level of friction coefficient sufficient to achieve good travelling performance.
Several attempts to satisfy the requirements for smoothness and travelling performance which oppose each other have been made. In one such attempt, magnetic tapes are made irregular on one surface where no magnetic layer is formed. This may be achieved by coating a magnetic tape with a suitable resin composition on the back surface thereof. However, the back coating procedure requires an additional step which increases production cost and labor. In addition, uniform formation of the back coat layer is difficult and thus not practical.
Another attempt is to incorporate inactive materials such as aluminium silicate, calcium carbonate, calcium phosphate, silica or the like in base films. However, this is not satisfactory in improving both electromagnetic characteristics and travelling performance at the same time.